10 million plus people reside within megacities. Amongst the lushness there is rising concern with the dangers of them.

We are now residing in the age of the city and materialism. Due to the intensification of mass industrialisation, politics, warfare, increase in global warming etc. human beings have gone through magnificent changes in migration from the rural areas in countries towards urban centres. Some cities could have up to a few thousand people which reside in them, however megacities are cities can reach up to 10 million people and more within a limited area.

There are now 23 megacities in the world, compared with just two 60 years ago. Just over half of the global population currently dwells in cities, and with the urban population expected to nearly double by 2050, that proportion is projected to approach 70%. The world’s largest megacity, Tokyo-Yokohama, joins two cities and multiple Japanese prefectures to cover 5,200 square miles, and it houses a population of some 37.5 million individuals.

Rapid urbanisation is taking a heavy toll on public health due to the rise of air pollution, also due to the tight cramped conditions in underground cities, there is health and safety dangers and also the spread of disease amongst the population. While greenhouse gas emissions on a per capita basis can be lower in dense urban areas, cities are still responsible for 70 percent of emissions worldwide, according to the United Nations Human settlements program. Coastal megacities and land based megacities are still prone to human disasters such as droughts, flooding, hurricanes etc. “Cities may become more uncomfortable spaces to live in the future.” says Alex de Sherbinin, a geographer at Columbia University’s Center for International Earth Science Information Network.

Overall, megacities are here to stay, it's time governments and humans intensify tackling the negative consequences, and research alternatives which could limit the harm from them.